Magnetostatics - Determine the magnetic field

Two wires carrying currents of 4A and 6A, respectively, are oriented perpendicular to each other and cross without electrical connection at the origin. Determine the magnetic field magnitude and direction at the point (2, 4).

[bI don't even know what equation to use for this. All we have learned is that F=qV x B. That doesn't seem to have much bearing on the problem at hand.[/b]

Don't know where to start...if anyone has a link to something that explains these types of problems that would be highly appreciated. The teacher has been teaching us a chapter of AP Physics a day and I am getting a bit left behind. Thanks.